The invention relates generally to security systems, and more particularly to security systems which communicate with a central monitoring station via a telephone line.
Present day security systems (i.e. intrusion and/or fire alarm systems) typically include a telephone dialer which is coupled to the alarm system and to a telephone line at the protected premises. When an alarm system is xe2x80x9ctrippedxe2x80x9d (i.e. intrusion, fire), the alarm system dials the telephone number of a central monitoring station. Upon answering by the central monitoring station, the alarm system transmits information to the central monitoring station so that police and/or firefighters may be dispatched to the protected premises. Many of the alarm systems"" telephone dialers are typically limited to the telephone number programmed by the vendor or installer. Therefore, users of such alarm systems are limited in choosing their central monitoring service provider.
An object of the invention is to provide a method and apparatus for rerouting the report call of an alarm system to a telephone number different from the preprogrammed one.
It is a further object of the invention to provide the user of the alarm system an option to choose any desired central monitoring station service provider without having to program the alarm system itself.
With these and other objects in mind, the present invention provides for a detector means for sensing both the voltage drop across a telephone handset line and the presence of dialing activity from the alarm system, whereupon it generates initiating signals to a microprocessor controller. When the microprocessor controller receives the initiating signals, it outputs both a switching signal and a pre-programmed dialing signal. A switching means responsive to the switching signal returns the telephone line briefly to an on-hook condition to reestablish dial tone and isolates the alarm system from the telephone line during the rerouting process. Upon reestablishing dial tone, a telephone communication dialer means responsive to the dialing signal, dials the telephone number of the desired central monitoring station. Once the dialing is complete, the alarm system is reconnected to the telephone line for data transfer to the central monitoring station.